1. Field of the Invention
The present invention relates to the method and compositions useful in the practice thereof, for treating or modifying bulk materials or formed articles such that they can be seen and identified under ultraviolet irradiation during their processing into other products including composites, manufactured articles, mixtures or the like, wherein the treating compositions can be made water dispersible such that they can be readily washed away from the products after the production operations have been performed, or wherein the compositions can be chemically tailored to be compatible with non-aqueous systems or materials such as various polymeric substrates, fuels, solvents, or the like.
Of particular concern is the use of the present method and compositions for visually inspecting formed articles such as different yarns, for any of a number of purposes hereinafter described, during processing of the yarns such as in the slashing, warping and weaving thereof into fabrics.
Another preferred embodiment of the invention is the use of the present method and compositions for visually inspecting compositions of polyurethane formed articles, thermoplastic formed articles, cured epoxy formed articles and silicone formed articles.
2. Description of the Prior Art
Heretofore, fluorescent materials have been employed in security paper or fibers or other materials whereby irradiation by selected wavelengths such as ultraviolet rays will cause emission of visible light for easy identification. Such technology is described in U.S. Pat. Nos. 4,655,788 and 4,451,530. The use of fluorescent materials such as organic dyes, permanently bound to yarn or the like for creating decorative effects or for use in security applications is disclosed in U.S. Pat. No. 4,623,579.
In the unrelated fields of the processing of formed articles such as fibers and yarns into fabric products, or the blending of particulate polymeric materials of different composition or color or the like, the use of fluorescent agents for the tracing or identification of the articles such as in monitoring the integrity of yarn or fiber during the slashing, warping or weaving operations would appear to have little if any use according to prior practices wherein the fluorescent material is permanently bound to the product, typically in an insoluble polymeric matrix. In this regard, the detection of broken yarn during such operations has been very difficult, particularly where close shades are being used and where the operator has to visually determine yarn fractures or other integrity problems.